January 7, 2025
Journal Article

Monte Carlo Simulations of 347H Stainless Steel Aging for the Synthetic Generation of Microstructures Under Creep Conditions

Abstract

A Monte Carlo simulation method capable of replicating the kinetics of M23C6 precipitation in 347H stainless steels was developed for the purpose of producing synthetic microstructures that approximate its microstructural evolution under aging periods of up to 10,000 hours at temperatures between 600 °C and 750 °C. To accomplish this, experimental data from the literature was used to parameterize simulations and replicate the nucleation and growth kinetics of M23C6 particles within 347H and similar austenitic stainless steel alloys. These simulations were found to have considerable fidelity to previous efforts to study the precipitation of M23C6 in other 300 series stainless steel alloys. Synthetic 347H microstructures were then generated that accounted the effects of aging temperature, duration, dislocation density, and the presence of boron within the microstructure. These simulations predict several key trends, those being that 1.) the size of M23C6 precipitates decreased with aging temperature and 2.) the growth rate of M23C6 particles decreased with aging temperature. Further, while 3.) the addition of dislocation density due to creep conditions resulted in increasing intragranular nucleation of M23C6 precipitates with increasing dislocation density, 4.) B additions within the microstructure led to modest increases in precipitate size above 700 °C, which indicates that more complex physics are necessary to account for the presence of B. The potential for images generated in this way to be used for image-identification algorithms will be discussed.

Published: January 7, 2025

Citation

Frazier W.E., A. Visweswara Sathanur, M. Taufique, R. Devanathan, and K.S. Kappagantula. 2024. Monte Carlo Simulations of 347H Stainless Steel Aging for the Synthetic Generation of Microstructures Under Creep Conditions. Metallurgical and Materials Transactions A - Physical Metallurgy and Materials Science 55, no. 10:4026–4034. PNNL-SA-177884. doi:10.1007/s11661-024-07477-7

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